ABSTRACT
Objective:To evaluate the feasibility, accuracy, effectiveness and safety of a novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction.Methods:A retrospective case series study was conducted to analyze the 35 patients with injury to the lower cervical spine or cervicothoracic junction who had been treated by a novel manual placement of cervical 7 pedicle screws at Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University from March 2015 to July 2021. There were 16 males and 19 females, with an age of (52.7±13.2) years. The core of this placement was to determine the entry point of cervical 7 pedicle screws. After the intersection of the upper edge of the cervical 7 lamina and the medial edge of the superior articular process was recorded as point A while the intersection of the lateral edge of the inferior articular process and the lower edge of the transverse process as point B, the intersection of the outer and middle 1/3 of the AB line was taken as the screw entry point, with the screw placement angle perpendicular to the lamina line or slightly inclined from 30° to 40° to the head side and outward. The length, diameter and placement angle of the cervical 7 pedicle screws were recorded and compared postoperatively between the left and right sides to explore the feasibility of this novel manual placement. According to the Rampersaud method, the screw positions were graded 1 week and 6 months after operation to evaluate the accuracy of this manual placement. The visual analogue scale (VAS) and the Japanese Orthopaedic Association (JOA) score were compared between preoperation, 1 week and 6 months after operation to evaluate the effectiveness of this placement. The postoperative complications were counted to evaluate the safety of this method. Loosening, displacement and breakage of the screws were observed by CT scanning at 6 months after operation.Results:This case series was followed up for (9.8±1.7) months. There was no significant difference in the length, diameter or placement angle of the screws between the left and right sides ( P>0.05). A total of 66 cervical 7 pedicle screws were placed. There was no change in the screw position grading at 1 week or 6 months after surgery. Grade A was achieved in 64 screws, Grade B in 2 screws, and Grade C or D in none. The VAS scores before operation, 1 week and 6 months after operation were respectively 4.4±1.7, 3.8±1.0 and 1.1±1.1, and the JOA scores respectively 6.7±2.2, 13.2±1.5 and 15.3±1.2. The VAS and JOA scores at 1 week and 6 months after operation were significantly improved compared with the preoperative values ( P<0.05). The improvement rates in JOA at 1 week and 6 months after operation were 62.7%±13.3 % and 83.9%±11.6%, respectively. There were no complications related to the placement of cervical 7 pedicle screws; there was no wound hematoma or infection. No loosening, displacement or breakage of the screws was observed by the 6-month follow-up. Conclusion:The novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction is feasible, accurate, effective and safe.
ABSTRACT
Introduction: Anatomical and morphometric aspects of seventh cervical vertebra are important for considerationof ventro-lateral approach in cervical spine surgery. Therefore, a detailed anatomical information of thedimensions of the vertebral elements is very important for successful surgical management in the degenerative,traumatic and neoplastic diseases of the cervical spine. Ethnic variations have also been reported in thesedimensions and there have been no morphometric studies performed in this area in the North Indian population.Materials and Methods: 60 dry Vertebra prominens vertebrae (C7) were obtained by maceration of the cadavers,made available for the purpose of dissection. Dimensions of vertebral body, lamina, spinous process andvertebral foramen of vertebra prominens(C7) were quantified for each vertebra. Morphological features includedmacroscopic appearance of Shape of vertebral foramen of vertebra prominens.Results: The length (VBL), superior width(VBSW), inferior width(VBIW), anterior height(VBAH) and posteriorheight(VBPH) of vertebral body of vertebra prominens (C7) was 14.21+2.95mm, 25.17+3.45, 24.89+3.25mm,11.72+1.88mm and 12.61+1.87mm respectively. Height(LH), length(LL) and width(LW) of lamina of were measuredas 14.47±1.72 mm, 22.23±2.46mm and 3.74±0.46mm. Length of the spine of vertebra prominens was found to be28.59+3.72mm. Maximum(widthmax) and minimum(widthmin) width of spine were 12.15+1.99mm and 6.22+1.53mm.Foramen diameter anteroposterior (FDAP) and transverse (FDT) was found to be 12.97+1.66mm and 22.85+2.46mmrespectively.Conclusion: Taking these measurements of vertebra prominens(C7) into consideration with combined effects ofaxial computed tomography, the diameters are valuable in correct estimation of spinal deformities and are ofinterest from anatomical, anthropological aspect and also from medicolegal point of view